package cn.dlike.LunarCalendar.util;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

/** 
 * <b>描述</b>: 日历转换工具类：阴历和阳历日期互换(阴历日期范围19000101~20491229)<br> 
 * @author liu 2015-1-5 
 */ 
public class CalendarUtil {
    //  private static final Logger logger = LoggerFactory.getLogger(CalendarUtil.class);  
    // 计算阴历日期参照1900年到2049年  
    private final static int[] LUNAR_INFO = {  
            0x04bd8,0x04ae0,0x0a570,0x054d5,0x0d260,0x0d950,0x16554,0x056a0,0x09ad0,0x055d2,  
            0x04ae0,0x0a5b6,0x0a4d0,0x0d250,0x1d255,0x0b540,0x0d6a0,0x0ada2,0x095b0,0x14977,  
            0x04970,0x0a4b0,0x0b4b5,0x06a50,0x06d40,0x1ab54,0x02b60,0x09570,0x052f2,0x04970,  
            0x06566,0x0d4a0,0x0ea50,0x06e95,0x05ad0,0x02b60,0x186e3,0x092e0,0x1c8d7,0x0c950,  
            0x0d4a0,0x1d8a6,0x0b550,0x056a0,0x1a5b4,0x025d0,0x092d0,0x0d2b2,0x0a950,0x0b557,  
            0x06ca0,0x0b550,0x15355,0x04da0,0x0a5d0,0x14573,0x052d0,0x0a9a8,0x0e950,0x06aa0,  
            0x0aea6,0x0ab50,0x04b60,0x0aae4,0x0a570,0x05260,0x0f263,0x0d950,0x05b57,0x056a0,  
            0x096d0,0x04dd5,0x04ad0,0x0a4d0,0x0d4d4,0x0d250,0x0d558,0x0b540,0x0b5a0,0x195a6,  
            0x095b0,0x049b0,0x0a974,0x0a4b0,0x0b27a,0x06a50,0x06d40,0x0af46,0x0ab60,0x09570,  
            0x04af5,0x04970,0x064b0,0x074a3,0x0ea50,0x06b58,0x055c0,0x0ab60,0x096d5,0x092e0,  
            0x0c960,0x0d954,0x0d4a0,0x0da50,0x07552,0x056a0,0x0abb7,0x025d0,0x092d0,0x0cab5,  
            0x0a950,0x0b4a0,0x0baa4,0x0ad50,0x055d9,0x04ba0,0x0a5b0,0x15176,0x052b0,0x0a930,  
            0x07954,0x06aa0,0x0ad50,0x05b52,0x04b60,0x0a6e6,0x0a4e0,0x0d260,0x0ea65,0x0d530,  
            0x05aa0,0x076a3,0x096d0,0x04bd7,0x04ad0,0x0a4d0,0x1d0b6,0x0d250,0x0d520,0x0dd45,  
            0x0b5a0,0x056d0,0x055b2,0x049b0,0x0a577,0x0a4b0,0x0aa50,0x1b255,0x06d20,0x0ada0  
    };  
  
    // 允许输入的最小年份  
    private final static int MIN_YEAR = 1900;  
    // 允许输入的最大年份  
    private final static int MAX_YEAR = 2049;  
    // 当年是否有闰月  
    private static boolean isLeapYear;  
    // 阳历日期计算起点  
    private final static String START_DATE = "19000130";  
  
  
    /** 
     * 计算阴历 {@code year}年闰哪个月 1-12 , 没闰传回 0 
     * @param year 阴历年 
     * @return (int)月份 
     * @author liu 2015-1-5 
     */  
    private static int getLeapMonth(int year) {  
        return (int) (LUNAR_INFO[year - 1900] & 0xf);  
    }  
  
    /** 
     * 计算阴历{@code year}年闰月多少天 
     * @param year 阴历年 
     * @return (int)天数 
     * @author liu 2015-1-5 
     */  
    private static int getLeapMonthDays(int year) {  
        if(getLeapMonth(year)!=0){  
            if((LUNAR_INFO[year - 1900] & 0xf0000)==0){  
                return 29;  
            }else {  
                return 30;  
            }  
        }else{  
            return 0;  
        }  
    }  
  
    /** 
     * 计算阴历{@code lunarYeay}年{@code month}月的天数 
     * @param lunarYeay 阴历年 
     * @param month 阴历月 
     * @return (int)该月天数 
     * @throws Exception 
     * @author liu 2015-1-5 
     */  
    private static int getMonthDays(int lunarYeay, int month) throws Exception {  
        if ((month > 31) || (month < 0)) {  
            throw(new Exception("月份有错！"));  
        }  
        // 0X0FFFF[0000 {1111 1111 1111} 1111]中间12位代表12个月，1为大月，0为小月  
        int bit = 1 << (16-month);  
        if(((LUNAR_INFO[lunarYeay - 1900] & 0x0FFFF)&bit)==0){  
            return 29;  
        }else {  
            return 30;  
        }  
    }  
  
    /** 
     * 计算阴历{@code year}年的总天数 
     * @param year 阴历年 
     * @return (int)总天数 
     * @author liu 2015-1-5 
     */  
    private static int getYearDays(int year) {  
        int sum = 29*12;  
        for(int i=0x8000;i>=0x8;i>>=1){  
            if((LUNAR_INFO[year-1900]&0xfff0&i)!=0){  
                sum++;  
            }  
        }  
        return sum+getLeapMonthDays(year);  
    }  
  
    /** 
     * 计算两个阳历日期相差的天数。计算不准确，已经废弃 
     * @param startDate 开始时间 
     * @param endDate 截至时间 
     * @return (int)天数 
     * @author liu 2015-1-5 
     */  
    @Deprecated  
    private static int daysBetween2(Date startDate, Date endDate) {  
        long between_days=(endDate.getTime()-startDate.getTime())/(1000*3600*24);  
  
        return Integer.parseInt(String.valueOf(between_days));  
    }  
  
    /** 
     * 计算两个阳历日期相差的天数。 
     * @param startDate 开始时间 
     * @param endDate 截至时间 
     * @return (int)天数 
     * @author liu 2017-3-2 
     */  
    private static int daysBetween(Date startDate, Date endDate) {  
        int days = 0;  
        //将转换的两个时间对象转换成Calendar对象  
        Calendar can1 = Calendar.getInstance();  
        can1.setTime(startDate);  
        Calendar can2 = Calendar.getInstance();  
        can2.setTime(endDate);  
        //拿出两个年份  
        int year1 = can1.get(Calendar.YEAR);  
        int year2 = can2.get(Calendar.YEAR);  
        //天数  
  
        Calendar can = null;  
        //如果can1 < can2  
        //减去小的时间在这一年已经过了的天数  
        //加上大的时间已过的天数  
        if(can1.before(can2)){  
            days -= can1.get(Calendar.DAY_OF_YEAR);  
            days += can2.get(Calendar.DAY_OF_YEAR);  
            can = can1;  
        }else{  
            days -= can2.get(Calendar.DAY_OF_YEAR);  
            days += can1.get(Calendar.DAY_OF_YEAR);  
            can = can2;  
        }  
        for (int i = 0; i < Math.abs(year2-year1); i++) {  
            //获取小的时间当前年的总天数  
            days += can.getActualMaximum(Calendar.DAY_OF_YEAR);  
            //再计算下一年。  
            can.add(Calendar.YEAR, 1);  
        }  
        return days;  
    }  
  
    /** 
     * 检查阴历日期是否合法 
     * @param lunarYear 阴历年 
     * @param lunarMonth 阴历月 
     * @param lunarDay 阴历日 
     * @param leapMonthFlag 闰月标志 
     * @throws Exception 
     */  
    private static void checkLunarDate(int lunarYear, int lunarMonth, int lunarDay, boolean leapMonthFlag) throws Exception {  
        if ((lunarYear < MIN_YEAR) || (lunarYear > MAX_YEAR)) {  
            throw(new Exception("非法农历年份！"));  
        }  
        if ((lunarMonth < 1) || (lunarMonth > 12)) {  
            throw(new Exception("非法农历月份！"));  
        }  
        if ((lunarDay < 1) || (lunarDay > 30)) { // 中国的月最多30天  
            throw(new Exception("非法农历天数！"));  
        }  
  
        int leap = getLeapMonth(lunarYear);// 计算该年应该闰哪个月  
        if ((leapMonthFlag == true) && (lunarMonth != leap)) {  
            throw(new Exception("非法闰月！"));  
        }  
    }  
  
    /** 
     * 阴历转换为阳历 
     * @param lunarDate 阴历日期,格式YYYYMMDD 
     * @param leapMonthFlag 是否为闰月 
     * @return 阳历日期,格式：YYYYMMDD 
     * @throws Exception 
     * @author liu 2015-1-5 
     */  
    public static String lunarToSolar(String lunarDate, boolean leapMonthFlag) throws Exception{  
        int lunarYear = Integer.parseInt(lunarDate.substring(0, 4));  
        int lunarMonth = Integer.parseInt(lunarDate.substring(4, 6));  
        int lunarDay = Integer.parseInt(lunarDate.substring(6, 8));  
  
        checkLunarDate(lunarYear, lunarMonth, lunarDay, leapMonthFlag);  
  
        int offset = 0;  
  
        for (int i = MIN_YEAR; i < lunarYear; i++) {  
            int yearDaysCount = getYearDays(i); // 求阴历某年天数  
            offset += yearDaysCount;  
        }  
        //计算该年闰几月  
        int leapMonth = getLeapMonth(lunarYear);  
  
        if(leapMonthFlag & leapMonth != lunarMonth){  
            throw(new Exception("您输入的闰月标志有误！"));  
        }  
  
        //当年没有闰月或月份早于闰月或和闰月同名的月份  
        if(leapMonth==0|| (lunarMonth < leapMonth) || (lunarMonth==leapMonth && !leapMonthFlag)){  
            for (int i = 1; i < lunarMonth; i++) {  
                int tempMonthDaysCount = getMonthDays(lunarYear, i);  
                offset += tempMonthDaysCount;  
            }  
  
            // 检查日期是否大于最大天  
            if (lunarDay > getMonthDays(lunarYear, lunarMonth)) {  
                throw(new Exception("不合法的农历日期！"));  
            }  
            offset += lunarDay; // 加上当月的天数  
        }else{//当年有闰月，且月份晚于或等于闰月  
            for (int i = 1; i < lunarMonth; i++) {  
                int tempMonthDaysCount = getMonthDays(lunarYear, i);  
                offset += tempMonthDaysCount;  
            }  
            if (lunarMonth>leapMonth) {  
                int temp = getLeapMonthDays(lunarYear); // 计算闰月天数  
                offset += temp; // 加上闰月天数  
  
                if (lunarDay > getMonthDays(lunarYear, lunarMonth)) {  
                    throw(new Exception("不合法的农历日期！"));  
                }  
                offset += lunarDay;  
            }else { // 如果需要计算的是闰月，则应首先加上与闰月对应的普通月的天数  
                // 计算月为闰月  
                int temp = getMonthDays(lunarYear, lunarMonth); // 计算非闰月天数  
                offset += temp;  
  
                if (lunarDay > getLeapMonthDays(lunarYear)) {  
                    throw(new Exception("不合法的农历日期！"));  
                }  
                offset += lunarDay;  
            }  
        }  
  
        SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd");  
        Date myDate = null;  
        myDate = formatter.parse(START_DATE);  
        Calendar c = Calendar.getInstance();  
        c.setTime(myDate);  
        c.add(Calendar.DATE, offset);  
        myDate = c.getTime();  
  
        return formatter.format(myDate);  
    }  
  
    /** 
     * 阳历日期转换为阴历日期 
     * @param solarDate 阳历日期,格式YYYYMMDD 
     * @return 阴历日期 
     * @throws Exception 
     * @author liu 2015-1-5 
     */  
    public static String solarToLunar(String solarDate) throws Exception{  
        int i;  
        int temp = 0;  
        int lunarYear;  
        int lunarMonth; //农历月份  
        int lunarDay; //农历当月第几天  
        boolean leapMonthFlag =false;  
  
        SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd");  
        Date myDate = null;  
        Date startDate = null;  
        try {  
            myDate = formatter.parse(solarDate);  
            startDate = formatter.parse(START_DATE);  
        } catch (ParseException e) {  
            e.printStackTrace();  
        }  
  
        int offset = daysBetween(startDate,myDate);  
  
        for (i = MIN_YEAR; i <= MAX_YEAR; i++){  
            temp = getYearDays(i);  //求当年农历年天数  
            if (offset - temp < 1){  
                break;  
            }else{  
                offset -= temp;  
            }  
        }  
        lunarYear = i;  
  
        int leapMonth = getLeapMonth(lunarYear);//计算该年闰哪个月  
        //设定当年是否有闰月  
        if (leapMonth > 0){  
            isLeapYear = true;  
        }else{  
            isLeapYear = false;  
        }  
  
        for (i = 1;  i<=12; i++) {  
            if(i==leapMonth+1 && isLeapYear){  
                temp = getLeapMonthDays(lunarYear);  
                isLeapYear = false;  
                leapMonthFlag = true;  
                i--;  
            }else{  
                temp = getMonthDays(lunarYear, i);  
            }  
            offset -= temp;  
            if(offset<=0){  
                break;  
            }  
        }  
  
        offset += temp;  
        lunarMonth = i;  
        lunarDay = offset;  
  
//        return "阴历："+lunarYear+"年"+(leapMonthFlag&(lunarMonth==leapMonth)?"闰":"")+lunarMonth+"月"+lunarDay+"日"; 
//        return lunarYear+"年"+lunarMonth+"月"+lunarDay+"日";
        return lunarMonth+"月"+lunarDay+"日";
    }  
}
